[ConeFusion]

Ok, my initial burst of questions, continued:

One thing that surprised me while looking through the specs was that the Elise doesn't seem to have an LSD. I think I saw a comment somewhere saying that it was "not needed" on this car. Would anybody care to elaborate? I would have expected that a LSD would help any car to put the power down out of a tight corner.

 

[MotorCade]

Actually, I believe one of the differences between the US celica transmission and the Euro transmission is that the Euro type comes with the LSD. I read it at a german website, however, and I don't remember which one... so I could be mistaken. Toyota makes a clutch type LSD unit for this transmission, so it can easily be fit if you desire. A quaife type unit was available for a few years as well, and a company called monkey-wrench racing is supposedly attempting to get a production run of those.

As to your question, however... a LSD will help any car put power to the ground as it is accelerating out of a corner. Even lower powered cars such as miatas. Ask any spec miata racer whether or not a LSD unit is necessary to be competitive...

The point is to prevent the inside tire from spinning and not putting power to the ground on that side.

Cade

 

[ConeFusion]

So is it going to have the same transmission as a Celica? I found conflicting information on that. If the same differentials fit, I guess that would make it easier to find an aftermarket one if necessary.

The Miata is a good comparison, and I know that the models with LSD are normally preferred.

 

[MotorCade]

Right, it will have the same transmission as the European Celica. (close ratio gears) I should have been more clear.

LSD is definitely a worthwhile upgrade, (if it doesn't have it) and suits the corner carving nature of this car.

 

[meat]

It's been found that a LSD or equivalent (Quaife unit) isn't needed on the Elise/Exige until you go over 200hp and start using slicks.

I, to date, have not had any issues with lifting an inside tire on the Exige. I will be upgrading to the UCR gearbox over the winter as well as the Dynamics dampers/springs so I may fit the Quaife diff while the trans is apart. We'll see.

 

[MotorCade]

That surprises me somewhat... even the 110 hp miatas find an extra second or sometimes two on the track with LSD. And they have 400-600 lbs over the Elise. This car is pretty close to the 200 hp mark as it comes over here, I would think it would be a definite benefit to add the LSD, if your driving ability warrants it. Can you elaborate?

Also thinking that just about anyone wanting to take this thing on the track will probably do at least a sport exhaust and intake. Which will likely bump them up to that 200 hp mark.

Cade

 

[and]

..and not considering the track, I can spin the inside tires of my Miata in sharp city-type corners in the wet. Makes me want to have a LSD for rain driving..

Are there any handling downsides to having a LSD?

 

[Randy Chase]

Are there any handling downsides to having a LSD?

Not much really. The real downside is a little extra weight.

 

[meat]

Let's keep in mind that the Elise has a bit more weight over the rear wheels than in a Miata. Also, the stiffness of the car helps keep the rear planted as well (not so much roll).

As a downside, the Quaife unit can cause some issues with stability as it starts to work from what I've been told.

Bottom line I guess is the Quaife unit for my car costs about $800 and it is NOT easy to install. So, until the car is apart for another reason or I have serious issues with the car I don't see the need for the "upgrade".

Also, with Lotus electronics, etc - you may want to wait on making HP gain claims.

 

[Randy Chase]

Let's keep in mind that the Elise has a bit more weight over the rear wheels than in a Miata. Also, the stiffness of the car helps keep the rear planted as well (not so much roll).

Agreed on stiffness. My experience though is in lightweight midengined cars.

 

[meat]

Randy - the comments were not directed at you.

I get tired of people talking about upgrading this and that. Drive the car first!!!

Let me know the next time you are faster around a track than a Viper or Vette in a 190hp car.....

These cars aren't "normal". They are highly tuned to go around corners fast from the factory. An upgraded Lotus suspension option is going to give you cornering speeds that you only used to dream about. You are, however, going to have to live with not being the fastest car down the straights. Fine with me - I have more fun outbraking and outturning almost every car on the track.

The outbraking is really fun - the Vipers and Vettes brake at 4-500 feet and I go down into the 150-200 feet area before I start. You can make up lots of ground like that. Not to mention you can carry more speed through the turn than they can.

Rant off......

 

[BryanH]

So the European spec Elise has LSD? It looks like it in this video of an S1 hooning around an airfield: http://www.jimbocam.com/elvington/vA/elvA-j5goon1.wmv

I have a few years experience racing mid-engined cars (slower than the Elise though) and LSD doesn't seem to be necessary in some cases. When stock my '87 MR2 had no need for LSD at all, there were no problems getting the power down or lifting the inside rear wheel. That is probably due to the whopping 112hp and 97ft-lbs and complete lack of any rear sway bar. But since I've upped the power and torque (about 140hp and ft-lbs) I do have the occasional problem of spinning the inside rear tire as I try to exit a corner quickly. An aftermarket LSD in this car will just make it understeer on corner exit, unless other significant changes are made to the suspension.

So what's my point in all this? I don't know. Perhaps it's to say that I'm surprised the upcoming US Elise, given its high power to weight ratio, won't have LSD. It would be great if the US car could do long showy powerslides as seen in the above video. Not that that's the fast way around, but it's fun. IMO there is nothing quite like the control of a well matched LSD. Having driven a stock Honda S2000 on track, the way you can control the rear end with LSD is nothing short of heavenly. I only hope the Elise can offer that experience of steering on the throttle. I will drive one... some day.

 

[Tripledigits]

A Torsen type LSD will essentially become an open diff with the inside rear tire off the ground. Clutch type LSDs do not have this problem. I've been having this issue in my Supra in Solo2 this season, and ended up tuning the car with no rear bar. Ideally, all 4 tires will stay on the ground in all corners, since alot of rubber is lost for traction with wheel lift.

I understand the US Elise will have no rear bar - Carroll Smith would be happy.

My experience with Torsen type LSDs in different cars has been positive - I believe it promotes a faster corner exit than an open diff. Maybe Lotus knows the status of the differential already??

Cheers,

Jeff

 

[moose]

I have never heard of anyone fitting LSD to an elise - you just don't need it. There's no rear ARB either.

Lotus do an LSD kit, I'd love to know how many they've sold!

>>So the European spec Elise has LSD? It looks like it in this video of an S1 hooning around an airfield: http://www.jimbocam.com/elvington/vA/elvA-j5goon1.wmv

No, jimbo just drives like a nutter

 

[John Stimson]

If you lift a rear wheel off the ground in an Elise before you lift a front, you've got other problems...I don't think that having a preload or clutch style differential would be any different than having a helical differential in almost any situation. Two wheels off the ground is the only time it's likely to matter. I don't know how likely that is with the Elise. I have seen it briefly, in extreme circumstances (Hoosier DOT competition radials on the grippiest concrete autocross sites in the USA) on taller cars: stock Miatas, stock S2000s, and even a stock MR2 Spyder or two. I would think that the Elise's lower center of mass coupled with its rearward weight bias would tend to keep the inside rear tire on the ground.

Bravo for no rear anti-sway bar! S2000s are plagued by wheelspin, even with a LSD, and I think it's because of the enormous rear anti-sway bar. Honda is shrinking that bar for 2004, which is probably a good thing, especially when they are giving the car more torque with which to spin the wheels

 

[BryanH]

Reason I asked about that video is because I can see the outside (loaded) rear tire spinning happily along. In an open diff car my experience is only the inside rear wheel will spin when you've given it too much power. That kills forward momentum and makes oversteer control pretty difficult. If both rear wheels are spinning, as in that video, one has much more control over the attitude of the car.

If the car in that video does not have LSD then Lotus have really done some amazing things with suspension!

I've driven a couple front-engined cars on the track with LSD (AE86 and S2000). The way they tuck the nose in when you apply the power correctly gives me warm fuzzies.

Edit to respond to John... I love the S2000 just the way it is. Maybe there are wheelspin problems at autocross events, but on a road course the car is gold. If you apply throttle smoothly there are no wheelspin problems. In fact it's very easy to drive at the limit due to its linear build of power. I really can't get over how fun that car was. Can't imagine what an Elise must be like.

 

[LeftyS7]

LSD has been useful

Owning a '90 Caterham Super Seven and using it for Autocrossing, the first upgrade I did was to install a LSD. Our Miata has the sports package which includes a LSD and it makes a BIG difference in both cars for Autocrossing! Probably not necessary for street use and only slightly helpful for track use. I am hoping that the sports package will include one. John Lefcourte

 

[jahwerx]

Clutch v. Torsen

I think an advantage of the Torsen-style LSD is that it works without having to sense any wheelspin in order to transfer power to the stickier side. Also the torque bias of the "grippier" wheel is a factor (like 3X or 5x) of the torque that can be applied to the "less grippy" wheel (pardon my lack of technical terms.) Disadvantage someone already stated - a spinning wheel (in the air for example) makes Torsen useless since 3X nothing is nothing.

Apply the reverse logic for clutch type. Main disadvantege is that a wheel has to spin ever so slightly to engage the clutch. This is my understanding - I'd love to know if this is incorrect.

 

[tonykomo]

I have a Quaiffe ATB on my car. Personally, can feel the difference but only in high speed corners. Gives you a lot more confidence.

The Sport 190 also comes with an LSD as does the Exige. Have to say it's more of a total package thing though. Don't even bother with an LSD unless you're doing suspension, ARB, tyres etc.

As someone on here said, don't dwell on it until you've driven your Elise for some time. It takes a while to learn how to get the most out of it. And I'm sure there are people that will scoff at that but you just wait, and can be quite nerve racking.

 

[Randy Chase]

Latest (not totally official!) news is that LSD will be offered as an option.

I am not sure yet if it's an option only on the Sports Suspension package, or if it's an option for any Elise.